#include<iostream>
#include<string>
using namespace std;

int main()
{
	string str1 = "abcd", str2, str3;
	int len;
	
	cout << str2.size() << endl;
	str2 = str1;
	cout << "str1:" << str1 << " str2:" << str2 << endl;
	str3 = str1 + str2;
	cout << "str1 + str2:" << str3 << endl;
	len = str1.size();
	cout << "length:" << len << endl;
	getline(cin, str1);
	cout << str1;
	
	return 0;
}
